1. Field of the Invention
The invention relates to an image processing apparatus, an image processing method, and a program storage medium and, more particularly, to an image processing apparatus, an image processing method, and a program storage medium, in which data can be outputted again on the basis of inputted print data.
2. Related Background Art
In recent years, the realization of high speed printing of a plurality of copies has been a large problem in an image processing apparatus, such as a page printer or the like, which analyzes a print job described by a page description language (hereinafter, abbreviated to “PDL”) or the like, and outputs a corresponding page image.
Hitherto, it has been a general application to sort and staple the necessary number of copies by copying the necessary number of sheets, using a copying apparatus, on the basis of an output result derived by a printer. However, the need to output a plurality of copies of an original by a printer is increasing. Also, because the operation has to be performed twice, a picture quality of a copy obtained by the copying apparatus is inferior to that of an original outputted by the printer, and the like.
There are the following conventional methods for processing a plural copy print at a high speed.
The first method is a method whereby only one copy of a print job is transmitted from an external apparatus, such as a host computer or the like. The the print job is spooled into an external storing device such as a hard disk, or the like, equipped on the printer side, and an analysis of a PDL and a print are repeated the same number of times as the designated number of copies. According to the first method, since a data transfer can be accomplished only one copy at a time, it is effective particularly in a case where the apparatus is connected by an interface of a low transfer speed.
In a case where the apparatus is equipped with a mechanical sorter as a finishing apparatus, a plurality of copies can be printed (what is called a page copy) by sequentially outputting respective pages, as many as the number of copies, to different paper ejection bins. For example, when three copies of data (where 1 copy=2 pages) are outputted, first, page 1 is ejected to bins 1 through 3 and page 2 is subsequently ejected to bins 1 through 3. Usually, an intermediate object which is generated by analyzing the PDL data is repetitively rendered the same number of times as the number of copies, thereby outputting the same page. Therefore, it is sufficient to analyze the PDL data once per page. Accordingly, in the plural copy print method using both page copy and a mechanical sorter, engine performance of the printer can be made the most of, as long as it is limited to an output of the same page. Further, since the rendered page data which has been outputted can be also successively erased, a memory can be efficiently used.
The second method is a method whereby a page image (bit map image) rendered at the time of the PDL analysis of the first copy is stored in an external storing device such as a hard disk or the like together with page information indicative of an outputting order or the like and the rendered page image is reused at the time of outputting the second and subsequent copies (the print data of only one copy is received in a manner similar to the first method). According to the second method, the page image is read out from the hard disk and directly shipped to an engine, thereby outputting the second and subsequent copies. According to the second method, since the print data need not be analyzed when the second and subsequent copies are outputted, the page image can be outputted at a high engine speed irrespective of the contents of the print data.
The conventional techniques, however, have problems as will be explained hereinbelow.
That is, according to the first method, since the PDL data is analyzed the designated number of times, particularly, in case of complicated data contents of a heavy analysis load, the page image cannot be outputted at a high speed.
Even in the case where the apparatus has the mechanical sorter, when the total number of copies to be outputted exceeds “the maximum number of copies which can be sorted at once by the sorter”, it is necessary to analyze the PDL each time. That is, if (the number of copies=8) is designated for the sorter having seven paper ejection bins, the PDL has to be analyzed twice (the first copy and the eighth copy).
According to the second method, although it is sufficient to analyze the PDL once irrespective of the designated number of copies, an overhead at the time of storing the page image onto the HD or the like upon outputting the first copy occurs. Consequently, there is also a case where the outputting speed becomes contrarily slow in dependence on the data.